From eastern Europe to southern Iraq, the U.S. military faces a difficult problem: Adversaries pretending to be something they're not -- think Russia's "little green men" in Ukraine. But a new program from the Defense Advanced Research Projects Agency seeks to apply artificial intelligence to detect and understand how adversaries are using sneaky tactics to create chaos, undermine governments, spread foreign influence and sow discord. This activity, hostile action that falls short of -- but often precedes -- violence, is sometimes referred to as gray zone warfare, the'zone' being a sort of liminal state in between peace and war. The actors that work in it are difficult to identify and their aims hard to predict, by design. "We're looking at the problem from two perspectives: Trying to determine what the adversary is trying to do, his intent; and once we understand that or have a better understanding of it, then identify how he's going to carry out his plans -- what the timing will be, and what actors will be used," said DARPA program manager Fotis Barlos.